Electric relay device for indicating weak currents



Feb. 21, 1933. R H, GEFFCKEN ET AL 1,898,046

ELECTRIC RELAY DEVICE FOR INDIGATING WEAK CURRENTS Filed Nov. 12, 1924 Witnesses l7nvento rs I Patented Feb. 21; 1933 UNITED STATES PATENT; OFFICE BUDOLF N HEINRICH GEFFCKEN AND BUDOLF HANS RICHTER, OF LEIPZIG, GERMANY, ASSIGNOBS 'TO'.BADIO PATENTS CORPORATION, OF NEW YORK, N. Y A

CORPORATION or new YORK ELECTRIC RELAY DEVICE FOR INDICATING WEAK CURBENTS Application filed November 18, 1924, Serial No. 749,573, and in Germany November 15, 1923.

Our invention relates to electric relay devices, and it has special relation to relays of the character described which may be actuated by extremely weak currents.

More particularly our invention contemplates the application of the well known phenomenon that an electric discharge or arc may be produced between two electrodes far more easily than usual if the gas between the said electrodes is ionized. That is, an electric discharge between two electrodes, upon which a potential is impressed which is less than the normal potential necessary'to cause an are between said electrodes, may be initiated if the gas in the space between the electrodes is brought to an ionized condition. By making use of this phenomenon, we have been able to indicate or utilize extremely weak currents, since only very small quantities of energy are necessary in order to produce the required ionization.

Some'of the workers in this art, for instance Zehnder. (see Annalen der Physiki, Vol. 47, page 77 (1892); and Vol. 52, page 34 (1894)), have attempted to demonstrate the reception of Hcrtzian waves by producing an ionization between two spherical auxiliary electrodes, this ionization being effected by a low energy discharge produced by Hertzian waves. The ionization thus pro: duced served to start a luminous discharge between two primary or main electrodes. In the demonstration made by Zehnder, however, the auxiliary electrodes were connected only with an oscillatory circuit, and it usually followed that in this oscillatory circuit, it was necessary to produce a potential which was substantially equal to the arcing potential of the auxiliary gas (this being about 200 volts) in order to initiate the luminous discharge between the main electrodes; this, of course, necessitated an appreciable amount of energy being used.

One of the main objects'of our invention, therefore, is to arrange an arc or discharge tube with one or several auxiliary electrodes whereby the same may be practically used to indicate weak currents. \Ve markedly reduce the energy which is to be used to initiate the arc or the discharge by applyingan auxiliary potential to the auxiliary gap, this auxiliary potential being so adjusted that a low additional potential on this gap is sufiicient to exceed the discharge voltage of the auxiliary gap. By thus initiating the auxiliary discharge, the are between the main electrodes is started and this eventuates a current strong enough to operate any device, for instance, a relay.

We may, on the other hand, so'practice our invention that the energy necessary for initiating the discharge may be still further reduced; that is, we may produce the ionizing auxiliary discharge between an auxiliary electrode and a main electrode, the latter being preferably the cathode.

By practicing our invention in the above manner, and particularly by advantageously arranging the electrodesand the connections, we have succeeded in making a practicable relay device which will operate with a very weak current. Other advantages will, of course, be apparent when the following specification is read in connection with the accompanying drawing.

The accompanying drawing illustrates a number of embodiments of our invention, wherein:

Fig. 1 is a diagrammatic View of the circuits utilized when our invention is employed for receiving electric waves;

Fig. 2 illustrates the circuits as used when our invention is applied. to a telegraph system; and

Fig. 3 illustrates the application of the invention for measuring purposes.

' In Fig. 1 the auxiliary electrode 4 is arranged between the main electrodes 2 and 3 of the tube 1, it being noted that by this means the discharge potential of the auxiliary gap 3, 4 is markedly lower than that of the main gap 2, 3. The direct current the electrodes 3 and 4 is adjusted to be just below the discharge potential of the gap between said electrodes. The oscillatory circuit 9 acts upon the grid of the valve 10 and is connected in such a manner that when energized by an antenna (not shown in the drawing) it causes the current from the valve to diminish, this latter being equivalent to increasing the voltage between the cathode and the plate of the valve. Through such a voltage increase, the discharge potential of the auxiliary gap 3, 4 is attained and the rela starts as above indicated.

ere again an extremely weak current may be detected by starting the are between the main electrodes 2 and 3 and a device 7, such for instance as a Morse recorder, will be actuated. A. circuit breaker 12, as shown in the circuit, acts to open the main circuit. When the energy of the antenna ceases to act upon the oscillatory circuit 9 the main discharge between electrodes 2 and 3 also ceases and is not started again until the voltage in circuit 9 is again built up. In this connection, it is to be noted that the latter circuits will give the desired results only when the circuit breaker frequency is above that of the highest signal frequency. This application of our invention is especially useful in the reception of radiant energy.

Referring now to Fig. 2 our invention is illustrated as being used with a telegraph system. In this figure, the main circuits whereby the electrodes 2 and 3 are energized,

include'a high resistance member 13 and a condenser.14 which shunt the tube 1, the

key 15 being connected to telegraph wires.. The telegraph wire connected to the auxiliary electrode 4 is at substantially ground .potential, and since the battery 6 is grounded at 19, a direct current voltage is impressed upon the auxiliary gap 3, 4, which may be just below the discharge potential of said gap. ,Even if the telegraph wires have a very high resistance (that is 100000 ohms) the weak current, which passes upon the closing of the key 15, is suflicient to increase the v0 tage of the auxiliary electrode 4, and

said voltage attains the discharge potential.

of the auxiliary gap 3, 4. When the main discharge between theelectrodes 2 and 3 is thus started, the condenser 14 discharges through a telephone, diagrammatically represented at 16. Because of .the high resistance, however, the discharge cannot be maintained and the arc fails to be re-started until the condenser becomes re-chargegl up to a certain value of voltage. This latter character of interrupters is of considerable value -if used in connection with the relay of our ed not only to indicate weak currents, but, moreover, to measure the same.

In Figure 3, we have diagrammatically illustrated a circuit for effecting such measurement of weak currents. The arrangement is very much like that of Fig. 2 with the addition that a condenser 17 is placed in the circuit of the auxiliary or initiating discharge electrode. A radio-active tube is represented at 18, that is a gas filled tube with two plate electrodes, one of which is treated with a radio-active compound. Such a tube allows only an extremely weak current to pass. In Fig. 3 this currentchargcs the condenser 17 until the potential of the auxiliary gap 3, 4 exceeds the discharge voltage thereof, whereupon a weak discharge passes said gap and serves to initiate a heavy discharge between the main electrodes 2 and 3. This latter arc,

however, is automatically interrupted, as

aboveindicated. It is our experience that after the interruption of the discharge, the potential of the auxiliary electrode 4 remains at a value which is just below that normally required to cause a discharge to pass the auxiliary gap. Consequently a low additional charge on the condenser 17, caused by the extremely weak currents passing the radioactive tube 18, is sufiicient to re -establish the discharge otential of the auxiliary electrode 4 and the discharge phenomenon periodically repeats, the frequency of the same increasing as the ionization current from the tube 18 increases and this frequency again increasin if'the capacity of the condenser 17 diminis es. As the frequency of the current pulsations becomes greater, the average intensity of the current in the main electrode circuit increases. Such an increase can be measured by a device 7 which may, for instance, comprisean integrating meter for measuring such average values. As before pointed out, such measurement is only possible if at the moment of arcing the main electroldes have attained a sufiiciently high potentia It is necessary, therefore, in practicing our invention to choose the frequency of interrupting the main electrode circuit to thereby secure a frequency higher than the arcing frequency.

While we have described several embodiments of our invention, it will be apparent that those skilled in the art may make many changes therein without departing from the spirit and scope of the appended claims.

Having described our invention, what we claim as new and desire to secure by Letters Patent of the United States, is

1. An electrical relay device for switching considerable current by extremely weak current, comprising a gas discharge tube, solid main electrodes and an auxiliary electrode situated therein, said main electrodes being connected to a source of controlled energysupply of too low a value normally to produce ionization and start a discharge means for imposing an auxiliary potential upon said auxiliary electrode, further means for imposing controlling potential upon said auxiliary electrodes, said auxiliary potential being of such value that upon the imposition of a low controlling potential the tube becomes ionized and a low voltage are discharge is started between said main electrodes.

2. An arc electrical rela device for switching considerable current y extremely weak current, comprising a gas discharge tube,'s'olid cathode and anode electrodes situated therein, an auxiliary electrode between said main electrodes and influencing their electric field,

. said main electrodes being connected to a source of energy supply of too low a value normally to produce ionization and start a discharge therebetween means for imposing an auxiliarly potential upon said auxiliary electrode further means for imposing controlling potential upon said auxiliary electrodes, said auxiliary potential being of such value that upon the imposition of a low additional controlling potential the tube becomes ionized and a low voltage are discharge occurs between said auxiliary electrode and the cathode, thus initiating the discharge be-v tween said main electrodes. y

I 3. An electrical relay device for switching considerable current by extremely weak current, comprising a gas discharge tube, solid main electrodes therein, an auxiliary electrode situated between said main electrodes and adapted to influence the electric field therebetween, said main electrodes being connected to a source of energy supply of too low a value normally to produce ionization and start a discharge therebetween, means for imposing a biasing potential upon said auxiliary electrode, means for imposing a further low controlling potential upon saidauxiliary electrode for initiating a low v0ltage discharge between said main electrodes by ionizing the space between the auxiliary electrode and one of the main electrodes, and an interrupter device in the circuit of said main electrodes, said interrupter being actuated by thedischarge current between said main electrodes.

4. An electrical relay device for switching space between the auxiliary electrode and one of the mam electrodes, and an automatically recurring interrupting device connected in the circuit of said electrodes.

I 5. In an electric'relay for switching considerable current by extremely weak current, a vessel filled with a gaseous atmosphere, two solid main electrodes disposed therein to form a discharge gap, an auxiliary electrode to form an auxiliary gap together with one of said electrodes, said main electrodes being connected to a source of energy supply of too low a value normally to ionize said gap and start a discharge therebctween, means for imsaid main electrodes to form an auxiliary discharge gap with one of said main electrodes, said main electrodes being connected to a source of controlled energy supply of too low a value normally to ionize said gap and start a discharge therebetween means for imposing a biasing potential upon said auxiliary electrode, means for imposing further controlling potential upon said auxiliary electrode, said biasing potential being of such value that upon imposition of an extremely weak controlling potential upon said auxiliary electrode said auxiliary discharge gap becomes ionized, initiating the discharge between said main electrodes.

7. In an electric relay device for switching considerable current by extremely weak current, comprising a glass tube filled with a gaseous atmosphere, solid and fixed cathode and anode electrodes situated within said tube to form a discharge gap, an auxiliary electrode within said tube arranged intermediate said cathode and said anode to form an auxiliary discharge space together with said cathode, said cathode and anode being connected to a source of controlled energysupply of too low a value normally to ionize said gap and produce a discharge therebetween, means for imposing biasing potential upon said auxiliary electrode, means for imposing further eontrollingpotential upon said auxiliary electrode. said biasing potential being of such "alue that, upon the further imposition of an extremely weak controlling potential upon said auxiliary electrode, an ionizing discharge of said auxiliary space is started initiatin the main discharge between said cathode an said anode.

. 8. In an electric relay system for sw1tch1ng considerable current by extremely weak cur- 5 rent, comprising an input c1rcu1t carrying weak controlling currents and an output 011- cuit carrying heavy controlled currents, a gas tube including solid main electrodes inserted in said output circuit, a source of potential 1 in said output circuitof too low a value normally to produce ionization and start a discharge between said main electrodes of said tube, an auxiliary electrode within said tube connected to said input circuit, means to impose a biasing potential upon said auxiliary electrode, further means for imposing controlling potential upon said auxiliary electrode, said biasing potential being of such --value that, upon the further imposition of an extremely low additional controlling potential derived from said input currents, said gap becomes ionized and a low voltage are discharge is produced between said mam electrodes. I

9. In an electric relay system for switching. considerable current by extremely weak current, comprising an input circuit carrying weak controlling currents, an output c rcmt to carry heavy controlled currents, a discharge tube filled with a gaseous atmosphere and including solid anode and cathode electrodes inserted in said output circuit, a source of operating potential connected in said out-,

put circuit of too, low a value normally to produce ionization and start a discharge between said cathode and said anode, an auxiliary electrode arranged intermediate said cathode and said anode and connected to said input circuit to form an auxiliary discharge path means for imposing a biasing potential upon said auxiliary electrode, further means for imposing -a controlling potential upon said auxiliary electrode, said biasing potential being of such Value that, upon the further imposition of an extremely low addiion a1 controlling potential derived from said controlling currents in said input circuit, an ionizing discharge is produced within said auxiliary discharge gap initiating the main discharge between said cathode and said anode. x

10. In an electrical system comprising an input circuit carrying weak controlling currents, an output circuit to carry heavy controlled currents, a discharge tube filled with a gaseous atmosphere, including solid main electrodes, a source of operating'potential 'inserted in said output circuit of too low a value normally to produce ionization and start a discharge between said main electrodes, an auxiliarly electrode connected to said input circuit to form an auxiliary discharge gap with one of said main electrodes, means for imposing biasing potential upon said auxiliary electrode, further means for imposin 'a controlling otential upon said auxiliaryelectrode, sai biasing potential being of such a value that, upon the further imposition of an extremely low additional controlling potentialderived from said controlling currents in said input circuit, an ionizing discharge occurs at said auxiliary ap initiating the dischargebetween said main electrodes and a high ohmic resistance means for imposing a biasing potential upon 'said auxiliary electrode, further means for imposing acontrolling potential upon said auxiliary electrode, said biasing potential being of such a value that, upon the further imposition of an extremely low additional controlling potential, an ionizing discharge occurs at said auxiliary gap initiatingthe discharge, between said main electrodes, a high oh'mic resistance in series with said electrodes and a condenser connected in parallel to said main electrodes.

12. In an electric system'comprising an input circuit carrying weak controlling currents, an output circuit to carry heavy controlled currents, a discharge tube filled with a gaseous atmosphere including solid main electrodes, a source of potential inserted in said output circuit of too low a value normally to produce ionization and start a discharge between said main electrodes, an auxiliary electrode connected to said input circuit to form an aux-iliary discharge gap with one of said main electrodes, means for imposing a biasing potential upon \said auxiliary electrode, further means for imposing a controlling potential upon said auxiliary electrode, said biasing potential being of such a value that, upon the further'imposition of an extremely low additional coniary electrode arranged intermediate said main electrodes, a source of electric energy supply connected to said main electrodes in series with a high ohmic resistance and being of too low a value to normally start a; discharge between said main electrodes, a condenser connected between said main electrodes, a further condenser connected between one of said main electrodes and said auxiliary electrode and further means to apply potential variations derived from the currents to be detected to said auxiliary electrode and the remaining one of said'main electrodes and a current translating device arranged in the output circuit connected to said main electrodes.

14. In a system for detecting extremely weak electric currents comprising in combination a discharge relay consisting of a tube filled with a gaseous atmosphere and having a cathode and anode electrode situated therein, an auxiliary electrode arranged intermediate said cathode and said anode electrode, a source of energy supply connected to said cathode and said anode in series with 'a high ohmic resistance, a variable condenser connected in parallel to said cathode and said anode, a further variable condenser connected in parallel to said auxiliary electrode and said cathode and a device carrying weak currents to be detected connected between i said auxiliary electrode and said anode and a current translating device in the output circuit connected to said cathode and said anode.

15. In anelectrical relay device comprising a vessel filled with a uniform gaseous atmosphere, solid main electrodes within said vessel, an auxiliary electrode within said vessel, sources of operating potential and biasing potential for said main electrodes and for said auxiliary electrode, respectively, further means for applying controlling potential upon said auxiliary electrode said operating and biasing potentials being of such value that normally substantially no ionizationis roduced of said atmosphere and said biasing otential being further 0 such value, that with the imposition of a low additional controlling potential ionization is started and a low voltage'arc discharge is initiated between said main. electrodes.

16. In an electrical system comprising an trolled currents; a gaseous discharge tube including solid main electrodes inserted in said out ut circuit; an auxiliary electrode within sai device connected to said input circuit; sources of operating potential and biasin potential for said mam electrodes and auxiliary electrode, respectively; further means for applying controlling potential upon sai auxiliary electrode, said operating and biasing potentials being input circuit carrying weak controlling curof such value that normally substantially no ionization is produced within said tube and said biasing potential being further of such value that with the imposition of a low additional controlling potential ionization is started and a low voltage are discharge initiated between said main electrodes; an electric reactance associated with said input circuit and connected to said auxiliary electrode to be electrically charged by the controlling currents in said input circuit to roduce controlling potential upon said auxiliary electrode for initiating a dis charge between said main electrodes.

' 17. In an electrical system comprising an input circuit carrying weak controlling cur-* rents; an output circuit to carry heavy controlled currents; a discharge device consisting of a vessel filled-with a uniform gaseous atmosphere; a pair of solid main electrodes situated within said vessel and connected in said output circuit; an auxiliary electrode within said vessel; sources of operating potential and biasing potential'for said main electrodes and said auxiliary electrode, respectively; said input circuit being connected between said auxiliary electrode .and one of said main electrodes; and an electrical condenser connected between said auxiliary electrode and the remainin one of said main electrodes to be chargefbythe controlling currents in said input circuit for producing controlling potential upon said auxiliary electrode to initiate the electric discharge between said main electrodes.

18. In an electrical system comprising an input circuit carrying weak controlling currents; an output circuit to can heavy controlled currents; an electrical ischarge device filled with a aseous atmosphere; main electrodes situated within said device and connected in said output circuit; potential means in said output circuit for alternately starting and stopping the electric dischar in said device; an auxiliary electrode within said device; said input circuit being connected to said auxiliary electrode; and an electric reactance connected to said auxiliary electrode and to said input circuit to be charged by the controlling currents in said input circuit for producin input potential upon said auxiliary electro e for controlling the electrical discharge of said device.

In testimony whereof we aflix our signatures.

RUDOLF HERMAN" HEINRICH GEFFCKEN. IUDOLF HANS RICHTER. 

